The aim of this research is to establish a cell line from chicken primordial germ cells that retains it potential to contribute to the germline with the goal of developing genetically modified chickens that produce pharmaceutical proteins in their eggs. Primordial germ cells obtained from the blood and the gonads can be cultured and retain their ability to contribute to the germline when injected into the bloodstream of stage 14-17 chicken embryos. However, only short periods of mixed cultures have been reported and the number of cells that have been generated is too small to be used for the production of transgenic chickens. If PGCs can be cultured and expanded for longer periods of time to achieve stable integration of transgenes while maintaining their competency to colonize the germline, it would provide a novel and reliable route to germline transmission. This application proposes to obtain PGCs from the germinal crescent to obtain a pure population of PGCs and to culture the PGCs under various conditions to obtain a cell line that retains the potential to contribute to the germline after injection into the bloodstream of a stage 14-16 (H&H) embryo.